The IMPACT Study will investigate the potential clinical benefit of the combined use of BIOTRONIK Home Monitoring (HM) technology and a predefined anticoagulation plan compared to conventional device evaluation and physician-directed anticoagulation in patients with implanted dual-chamber defibrillators or cardiac resynchronization therapy devices.

Composite Primary Endpoint: Kaplan-Meier Estimate of Patients Without a Stroke, Systemic Embolism, or Major Bleed [ Time Frame: From date of enrollment until date of primary endpoint event, assessed up to study exit, with a mean treatment duration of 2.0 years ] [ Designated as safety issue: No ]

The primary endpoint is to demonstrate whether early detection of atrial arrhythmias based on BIOTRONIK Home Monitoring technology combined with a predefined anticoagulation plan in the Home Monitoring Guided OAC group is superior to the Physician-Directed OAC group reflecting conventional care and physician directed treatment of AF in terms of risk reduction of the primary composite endpoint including stroke, systemic embolism, and major bleeding events.

Secondary Outcome Measures:

Rates of All-cause Mortality, Stroke (Ischemic and Hemorrhagic, Disabling and Non-disabling, Cardioembolic and Non-cardioembolic), and Major Bleeding, as Well as the AF Burden, Quality of Life, and Mean Heart Rate Reduction. [ Time Frame: 3 years ] [ Designated as safety issue: No ]

Secondary endpoints will be evaluated in a hierachical closed test procedure. If at the termination of the study, the result for the primary endpoint is found to have reached statistical significance, then Secondary Endpoints will be tested in turn for statistical significance at a 0.05 significance level. If at any stage, however, a non-significant result is found, no further testing of remaining secondary endpoints for statistical analysis will occur.

Home Monitoring is fully enabled and continuous remote surveillance data is available to investigators. Patients will be treated according to a predefined anticoagulation plan, which uses the total duration of AF/AFL combined with patients' CHADS2 score to determine the start, stop, and restart of OAC.

Drug: Home Monitoring Guided OAC

Active monitoring for atrial episodes through the automatic HM notifications (email, fax, short message service) is required. If the total duration over 48 consecutive hours reaches the predefined anticoagulation condition, and AF/AFL diagnosis is confirmed using the IEGM online, the site instructs the patient by telephone to start OAC. Clinicians continue to monitor patients using HM, and if freedom from AF/AFL reaches the predefined interval, stop of OAC therapy is requested over the telephone. Following stop of anticoagulation, any recurrence of AF/AFL requires restart of OAC therapy.

In Control (Group 2), Home Monitoring is active for Safety Net alerts, but the remote AF/AFL data is not revealed to the patient or treating physician. These patients receive physician-directed OAC consistent with current standards of care.

Safety Net data include:

ERI/EOS

Special Implant Status

Implant in Backup Mode (ROM)

VT/ VF Detection Inactive

Emergency Pacing

250 Ω > RV Pacing Impedance > 1500 Ω

Symptomatic VT/VF therapies including both ATP and shock

VT/VF storm

HM transmission failure >3 days

Drug: Physician-Directed OAC

Patients will receive physician-directed anticoagulation therapy based on conventional criteria.

Atrial fibrillation (AF) and atrial flutter (AFL) are common cardiac arrhythmias associated with an increased incidence of stroke in patients with additional risk factors. Oral Anticoagulation (OAC) reduces stroke risk, but because these arrhythmias are frequently intermittent and asymptomatic, start of OAC therapy is often delayed until electrocardiographic documentation is obtained.

The start, stop and restart of OAC based on a predefined atrial rhythm-guided strategy in conjunction with a standard risk-stratification scheme could lead to better clinical outcomes compared with conventional clinical care. The study is designed to demonstrate a risk reduction of both thromboembolism proximate to episodes of documented AF/AFL and bleeding potentiated by chronic OAC in the absence of AF. Verification of this premise would impact the clinical practice, providing evidence to physicians for the use of HM to guide OAC in patients with AF/AFL. The results of this study should demonstrate the clinical value of wireless remote surveillance of the cardiac rhythm and may define the critical threshold of AF/AFL burden warranting OAC or antiarrhythmic drug therapy in patients at risk of stroke

Able and willing to follow OAC therapy if the indication develops during the course of the trial

Able to utilize the HM throughout the study

Key Exclusion Criteria:

Permanent AF

History of stroke, transient ischemic attack (TIA) or systemic embolism and documented AF or AFL

Currently requiring OAC therapy for any indication

Patients who underwent successful AF ablation (sinus rhythm restored) and have not completed a minimum of 3 months of OAC therapy

Known, current contraindication to use of eligible OAC

Long QT or Brugada syndrome as the sole indication for device implantation

Life expectancy less than the expected term of the study

Contacts and Locations

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To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.
For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00559988